[AG-TECH] VPCscreen behaviour

[Andrew Rowley]

Hi,

Can you run a wireshark / tcpdump to make sure that the packets are actually given a TTL of 127?  I have seen problems specifically with Java and IPv6 where the TTL doesn't get set (and stays at 1 by default).  I know this isn't a Java program, but it could have the same problem somehow.  Try disabling IPv6 in this case.

The network people are unlikely to know about your software firewalls - these are the ones that run on your physical machine, rather than the network firewalls, which they control.  Software firewalls can stop specific pieces of software from transmitting or receiving network traffic (e.g. ZoneAlarm or the Windows Firewall (although XP doesn't block outbound traffic that I know of)).

Can I also check that vic (I assume it is vic you are using to transmit video) and VPCScreen are running on the same multicast address and port?

A summary of your problem is that multicast appears to be working (as attested to by the working video transmission and reception) but VPCScreen specifically doesn't seem to be getting out of the machine.  Is this correct?

Andrew :)

---------------------------------------------------------

   Andrew G D Rowley
   Senior Development Officer

   Research Computing Services
   The University of Manchester
   Devonshire House, Oxford Road
   Manchester, M13 9PL
 
   t :  +44 (0) 161 275 0685
   e :  Andrew.Rowley at manchester.ac.uk
   w :  www.manchester.ac.uk/researchcomputing
 
---------------------------------------------------------

> -----Original Message-----
> From: ag-tech-bounces at lists.mcs.anl.gov [mailto:ag-tech-
> bounces at lists.mcs.anl.gov] On Behalf Of Philippe d'Anfray
> Sent: 30 March 2010 10:59
> To: ag-tech at mcs.anl.gov
> Subject: Re: [AG-TECH] VPCscreen behaviour
> 
> Bonjour,
> 
> I made a test and  ttl is set correctly in multicast (see result from ps
> below: -t 127)
> 
> /usr/bin/VPCScreenCapture -N Philippe d'Anfray -E
> Philippe.d-Anfray at cea.fr -L Saclay France -P 00 -A
> 84a65c2f1472543ad50b4131460f306c -c H261AS -f 16 -b 800 -q 85 -t 127
> 224.2.141.24/61520
> 
> It does not seem to be a firewall issue , I checked with the "network"
> people here  (and we hame behaviour on two different sites...)
> 
> Cordialement
> 
> Philippe
> 
> 
> Andrew Rowley a écrit :
> >
> > Could this mean that the TTL is not being set correctly in VPC Screen
> e.g. the TTL is 0?
> >
> > The alternative is that VPCScreen is not open in the local software
> firewall (some firewalls need you to open outgoing and incoming traffic).
> >
> >
> >> -----Original Message-----
> >> From: ag-tech-bounces at lists.mcs.anl.gov [mailto:ag-tech-
> >> bounces at lists.mcs.anl.gov] On Behalf Of Philippe d'Anfray
> >> Sent: 26 March 2010 15:33
> >> To: ag-tech at mcs.anl.gov
> >> Subject: Re: [AG-TECH] VPCscreen behaviour
> >>
> >> Bonjour
> >>
> >> I just tried out various configurations, it confirms what you have
> >> already observed. The solution remains to use vpcscreen through a
> bridge
> >> for the producer ?
> >>
> >> 1) "Producer" Multicast only VPC screen
> >>
> >> Receiver Multicast same site: screen
> >> Receiver Multicast other site: nothing
> >> Receiver With Bridge (same site) : nothing  (except if we use "our"
> >> bridge which is on the same machine than the venue server)
> >>
> >> 2) "Producer" Multicast  VPC screen + Video
> >>
> >> Receiver Multicast same site: screen + video
> >> Receiver Multicast other site:  video only
> >> Receiver With Bridge (same site) : video only   (except if we use "our"
> >> bridge which is on the same machine than the venue server then we have
> >> both)
> >>
> >> 3) No problem when the producer uses a bridge.
> >>
> >>
> 
>